[7] The unconventional wing design also had the side effect of making it the first known aircraft to be capable of and perform the Cobra maneuver.

[17] Although other interceptors like the US Air Force's F-104 Starfighter were being conceived at the time, this fighter would have to undertake a role unique to Sweden; the ability to operate from reinforced public roads, which were to be used as part of wartime airbases.

[17] Preliminary studies found that the majority of critical issues posed by these requirements could be met with a delta wing configuration.

However, to obtain an aerodynamically desirable location, the forward fuselage needed to be extended, making the aircraft too heavy.

[17] The second prototype, equipped with an afterburner, unintentionally broke the sound barrier during its first flight while climbing.

The fuselage has a circular section, and the inboard portion of the wing is a large-chord surface which extended almost to the engine intakes.

For export customers, the Draken was outfitted with a Ferranti-built Airpass II fire-control radar, which was effective for acquiring various air-to-air or air-to-surface targets, along with a ground-mapping mode working in conjunction with the aircraft's navigation systems.

The rear portion, which was manufactured as a single piece alongside the rest of the inner wing, contained the engine and afterburner, bag-type fuel tanks, armament, main landing gear, and other systems.

[17] The flight control surfaces consisted of a rudder, along with inboard and outboard elevons, the outer sections being fitted with mass-balance weights.

[28] The principal armament was carried externally, up to four AIM-9 Sidewinder air-to-air missiles were carried on hard points beneath the wings and fuselage; alternative payloads include a variety of bombs and rockets, along with provisions for the installation of a pair of 30 mm cannons, located within each of the inboard wing panels.

[25] Due to a lack of knowledge regarding the then historically unproven design of the J 35's tailless double delta wing configuration, the plane encountered problems at the start of its service life.

[8][9][10] At the end of 1959, deliveries of the J 35A Draken commenced to the SAF, the first unit to receive the type being fighter wing F13, stationed at Norrköping.

[27] During March 1960, the Drakens of unit F13 participated in a three-day long exercise, flying by night and day while operating under a state of "highest readiness" throughout.

However, to assist pilots in converting to the type, Saab produced a small number of twin-seat J 35C trainer aircraft, the first of which having been completed during December 1959.

Among other things, it was powered by an improved engine fitted with an enlarged afterburner, a redesigned rear fuselage, a new Saab-built S-7 collision-course gunsight and fire-control radar, and integration with Sweden's STRIL 60 air defence control network.

The Draken J 35J was effectively a service life extension programme, which had been initiated as a result of the impending delivery of the new Saab JAS 39 Gripen having suffered several delays.

[32] All Drakens functioned as interceptors with limited air-to-ground capability; the sole exception to this rule was the Danish Drakens, which functioned as strike aircraft and were capable of carrying a mixture of AGM-12 Bullpup air-to-ground missiles, electronic countermeasures, and increased internal and external fuel storage.

[34] During the 1990s, Finland updated its 35XS fleet with new avionics, cockpit displays, navigational/attack systems, and electronic countermeasures; these were finally retired in 2000 to be replaced by F/A-18 Hornets.

They were followed from 1998 by a number of improved AIM-9P5's from Loral Corporation[36] In 2005, these Drakens were retired, having been replaced by former Swiss Air Force F-5 Tiger IIs, while waiting for new Eurofighter Typhoons to take their place in the long term.

[40] Due to manufacturing issues, delivery delays occurred for some J 35B subsystems, resulting in that the J 35B initially being delivered with only parts of the planned avionics installed.

[52] This resulted in there being two primary sub-variants of the J 35B historically: The base aircraft of the Saab 35B was identical to the J 35A2 and featured the same engine and afterburner,[52] the RM6BS and EBK66.

[59] Due to manufacturing issues, delivery delays occurred for some J 35D subsystems, resulting in that the two initial J 35D series being delivered with only parts of the planned avionics installed.

[59] Series 3, however, was delivered with complete avionics, resulting in there being two primary sub-variants of the J 35D initially:[59] The Saab 35D base aircraft differed quite a lot compared to previous variants.

[67] The aircraft was however fitted with a radar warning receiver and could mount a countermeasure pod named Kapsel KB with chaff and flare dispensers under the wings to increase its survivability.

For night missions it could carry an active infrared reconnaissance system of EG&G design in a pod fitted to a belly hardpoint.

[69] This variant had improved electronics and avionics, e.g. integrated radar, aim and missile systems, introducing the capability to use semi-active radar homing (SARH) and infrared homing (IR) versions of the Hughes Falcon missile, rb 27 (HM-55 / AIM-26B export) and rb 28 (HM-58 / AIM-4C export) respectively, originally intended for the J 35D.

This upgrade most notably included a Marconi 900 Series HUD and a Ferranti LRMTS (laser rangefinder and marked target seeker) which required a new nose to be installed on the F-35 and TF-35.

The last upgrade was completed in 1986 and updated the systems for weapon aiming and navigation accuracy to a similar capacity to those of the Danish Air Force's General Dynamics F-16 Fighting Falcons.

By 1993 the DKS also received countermeasures by installation of two Saab BOY 402 dispensers, capable of launching flares, chaff and expendable active decoys (EAD).

A small number of Drakens are still with civilian owners mainly in the United States, many former-operational aircraft have been preserved in the operating nations.